Bluetooth Low Energy beacon with FBAR-based oscillator-per-channel

ABSTRACT

Methods and systems described herein relate to broadcasting on a wireless channel. An example method includes generating, based on data, a data signal including one or more data packets, where each of the one or more data packets is a non-connectable and non-scannable data packet. The method further includes generating a plurality of RF signals of different frequencies using an oscillator circuit, directly modulating at least one of the RF signals, based on the data signal, to generate a modulated RF signal, amplifying the modulated RF signal, and broadcasting the amplified modulated RF signal on the wireless channel.

BACKGROUND

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.

Portable computing devices, such as personal computers, laptop computers, tablet computers, smart phones, wearable computers, and countless types of Internet-capable devices are prevalent in numerous aspects of modern life. For example, it is common for a single consumer to operate a smart phone, a laptop computer, a keyboard, and a mouse, possibly simultaneously. With increasing consumers of multiple portable devices, the demand for wireless technology continues to play a role in the use of such portable devices. As such, various forms of wireless technology have evolved to locally connect these portable devices for numerous applications. One wireless technology standard for exchanging data between multiple portable devices is popularly known as Bluetooth.

Bluetooth is commonly used for wirelessly connecting a portable device with one or more other portable devices over a short range. For example, Bluetooth may be used to connect a cell phone to a wireless headset, possibly allowing for hands-free use of the phone. In some instances, Bluetooth may also be used to connect the cell phone to audio speakers and a microphone of a motor vehicle, possibly allowing for hands-free use of the phone while operating the vehicle. Thus, numerous applications have allowed Bluetooth to grow as the standard wire-replacement protocol. In multiple applications, Bluetooth remains particularly attractive due to its low-cost solutions and protocols designed for low power consumption.

SUMMARY

Example embodiments herein disclose systems and methods capable of providing a signal via a Bluetooth low energy device. By using a Bluetooth low energy device to transmit a signal, significant power savings can be achieved.

In one example, a method of broadcasting an advertisement event on a wireless channel is provided. The method includes generating, based on data, a data signal comprising one or more data packets, where each of the one or more data packets is a non-connectable data packet. The method further includes generating a plurality of RF signals of different frequencies using an oscillator circuit and directly modulating at least one of the plurality of RF signals, based on the data signal, to generate a modulated RF signal. The method further includes amplifying the modulated RF signal and broadcasting the amplified modulated RF signal on the wireless channel, where the amplified modulated RF signal is associated with the advertisement event.

In another example, a broadcasting device is provided. The broadcasting device includes a packetizer that can generate, based on data, a data signal comprising one or more data packets, where each of the one or more data packets is a non-connectable data packet. The device further includes an oscillator circuit that can generate a plurality of RF signals of different frequencies, where at least one of the plurality of RF signals is directly modulated based on the data signal to generate a modulated RF signal. The device further includes a power amplifier that can amplify the modulated RF signal and an antenna that can broadcast the amplified modulated RF signal in a wireless channel as an advertisement event.

In yet another example, a system is provided. The system includes one or more one or more processors and a packetizer that can receive data from the one or more processors and generate, based on the data, a data signal comprising one or more data packets, where each of the one or more data packets is a non-connectable data packet. The system further includes a plurality of oscillators that can generate a plurality of RF signals of different frequencies, where each oscillator of the plurality of oscillators comprises an FBAR resonator, and where at least one of the plurality of RF signals is directly modulated based on the data signal to generate a modulated RF signal. The system further includes a power amplifier that can amplify the modulated RF signal and an antenna that can broadcast the amplified modulated RF signal in a wireless channel as an advertisement event.

These as well as other aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates computing devices located in proximity to a Bluetooth device, in accordance with an example embodiment.

FIG. 2 is a schematic diagram of a Bluetooth device, in accordance with an example embodiment.

FIG. 3 illustrates an advertisement packet, in accordance with an example embodiment.

FIG. 4A illustrates an oscillator, in accordance with an example embodiment.

FIG. 4B illustrates an oscillator, in accordance with an example embodiment.

FIG. 5A illustrates an oscillator, in accordance with an example embodiment.

FIG. 5B illustrates an oscillator, in accordance with an example embodiment.

FIG. 6A illustrates resonators, in accordance with an example embodiment.

FIG. 6B illustrates resonators, in accordance with an example embodiment.

FIG. 7 is a flow diagram of a method, in accordance with an example embodiment.

FIG. 8 is a block diagram of a Bluetooth device, in accordance with an example embodiment.

FIG. 9 is a block diagram of a computing device, in accordance with an example embodiment.

DETAILED DESCRIPTION

The following detailed description describes various features and functions of the disclosed systems and methods with reference to the accompanying figures. In the figures, similar symbols identify similar components, unless context dictates otherwise. The illustrative system and method embodiments described herein are not meant to be limiting. It may be readily understood that certain aspects of the disclosed systems and methods can be arranged and combined in a wide variety of different configurations, all of which are contemplated herein.

I. Overview

As noted, Bluetooth continues to grow as the standard wire-replacement protocol, and remains particularly attractive due to its protocols designed for low power consumption. Specifically, Bluetooth Low Energy (BLE), an extension of Bluetooth technology, may be attractive in applications where low power consumption may be advantageous.

In particular, BLE provides protocols for low power devices to communicate with multiple other devices. For example, consider a device that can be powered by one or more batteries. Further, consider that the device may be used in an application where replacing or recharging the one or more batteries may not be easily achievable. Accordingly, the device may be a low power device to preserve the charge of its power source. As such, the device may utilize BLE's protocols for communicating with other devices, such as computing devices (e.g., phones, laptops, and wearable computing devices). In an example, the low power device, e.g., a sensor, may utilize BLE protocols to transmit data to a computing device.

FIG. 1 illustrates an example scenario 100 of a device utilizing BLE protocols. The BLE protocols may be carried out by a low power device 102, such as a sensor. More specifically, the low power device 102 may include a BLE device, which may transmit a signal 104 according to BLE protocols. The power source of the BLE device may be one or more batteries. In some examples, the one or more batteries may be the one or more batteries of the device 102 that the BLE device is incorporated in. Further, the BLE device may transmit, according to BLE protocols, the signal 104 to the computing devices 106 and 108. However, it should be understood that the arrangement for the BLE device provided in FIG. 1 is for purposes of illustration only. For example, the BLE device may be included in any device, such as a phone (i.e., computing device), a digital television, a monitor, a tablet computer, wearable computing devices, and/or a human-interface device, among other possibilities. Further, in some embodiments, the BLE device may transmit a signal 104 to more than or fewer than two computing devices.

In scenario 100, each of the computing devices 106 and 108 may include a Bluetooth module, which may perform a Bluetooth scan to search for other Bluetooth devices and/or for signals from Bluetooth devices. In some embodiments, the computing devices 106 and 108 may scan for Bluetooth devices in order to pair with a Bluetooth device that is within a range of the Bluetooth scan of the computing devices. In other embodiments, at least one of the computing devices 106 and 108 may receive a signal from a Bluetooth device without pairing with the Bluetooth device. For example, at least one of the computing devices may receive a Bluetooth signal, e.g., signal 104, from the device 102 without pairing with the device 102.

Furthermore, scenario 100 may be a scenario where low power consumption by the BLE device is desirable. For example, the power source of the BLE device may have limited charge. In such a scenario, low power consumption by the BLE device may be desirable to extend the life of the power source. Typically, the power consumption of the BLE device may be governed by at least the configuration of the BLE device and/or the hardware of the BLE device. Accordingly, the BLE device may be described in relation to at least decreasing its power consumption.

II. Example Systems and Methods

FIG. 2 schematically illustrates a BLE device 200, according to an example embodiment. In some embodiments, the BLE device 200 may be included in other devices as a Bluetooth module. For instance, the BLE device 200 may be included in device 102 in scenario 100. Accordingly, the BLE device 200 may receive instructions from a processor and/or a memory of the device that it was included in. For instance, the BLE device 200 may interface with the processor of its host device via a Host Controller Interface (HCl). The BLE device 200 may receive a signal via the HCl, which may include data that may be transmitted by the BLE device 200.

As illustrated in FIG. 2, the BLE device 200 may include a BLE packetizer 202, an oscillator 204, a powertrain 210, and an amplifier 206. These components, as described herein, may be used to transmit a signal 104 from the BLE device 200. However, the BLE device 200 may not be enabled to receive a signal from another device. Thus, in some embodiments, the BLE device 200 may not be able to pair with or receive signals from other Bluetooth devices. Accordingly, the BLE device 200 may operate solely as a transmitter (also referred to herein as a “broadcaster” or as a “beacon”). For instance, in scenario 100, the BLE device may transmit a signal that may be received by the computing devices 106 and 108, without pairing with the computing devices.

Nonetheless, by eliminating at least some of the hardware that may be used to receive a signal, the power consumption of the BLE device 200 may be decreased. Additionally, eliminating at least some of the components for receiving a signal may decrease the manufacturing costs of the BLE device 200. Furthermore, the size of the BLE device 200 may be decreased, which may increase the potential applications and uses of the BLE device 200.

Returning to FIG. 2, the BLE packetizer 202 may receive a signal via the HCl. As explained elsewhere herein, the signal may originate from a processor of a device, which may be using the BLE device 200 as a Bluetooth module. Further, the signal that the BLE packetizer 202 may receive may include data, which may be included in the signal transmitted by the BLE device 200. The received signal may also include instructions indicative of the configuration of the BLE device 200, as the BLE device 200 transmits a signal. For example, the signal received may include parameters, such as encryption parameters, modulation parameters, a mode of operation of the BLE device 200, packet type, etc. Further, the parameters may be used to configure the BLE device 200 to generate a specific signal, which may be transmitted by the BLE device 200.

For instance, the signal received via the HCl may be indicative of a mode of operation of the BLE device 200. Within examples, the mode of operation may depend on the functionality of the BLE device 200. In some embodiments, the functionality of a BLE device 200 may be predetermined, as the BLE device 200 may be used in a specific application. In other instances, a user may provide an input indicative of the mode of operation to a computing device that may be using the BLE device 200 as its Bluetooth module. In particular, the user may provide an input to an input/output function of the computing device, possibly a graphical user-interface (GUI), to determine the mode of operation.

In some embodiments, the modes of operation of the BLE device 200 may include an advertising mode in which a BLE advertising protocol is used to periodically transmit data packets referred to as advertising packets (also referred to herein as “advertisement packets”). Despite their name, these data packets typically have no relation to “advertisements” in the marketing sense of the word. Rather, such data packets are referred to as advertising packets because they may be used to announce various data to one or more other devices capable of receiving the announcement. The advertising packets may carry data indicative of the BLE device 200 (e.g., a unique identification number (UID)). Alternatively or additionally, advertising packets may carry data indicative of or information from a device that may include the BLE device 200 as a Bluetooth module. For example, the host device may use advertising packets to possibly “pair” or connect with another device.

In other examples, the BLE device 200 may use advertising packets to transmit data that may have been stored in a memory of its host device, such as geographical data. In an example, the device 102 may be used in scenario 100 as a location beacon. Thus, the device 102 may use the BLE device 200 to transmit a signal that may provide one of the computing devices with precise geographical information included in advertising packets. In yet other examples, the BLE device 200 may be used to transmit advertising packets, which may include data that may have been collected by the host device. For example, the advertising packets may include meteorological data gathered by a sensor. Accordingly, the broadcast advertising packets may be received by a computing device (possibly referred to herein as a “receiver”) within a range of the BLE device 200.

Furthermore, in some instances, the mode of operation of the BLE device 200 may affect its power consumption. For example, the BLE device 200 may decrease its power consumption by using advertising protocols. Advertising protocols may maintain the low power consumption of the BLE device 200 by periodically broadcasting a signal during certain time intervals. During time intervals when the BLE device 200 is not broadcasting a signal, the BLE device 200 may idle or turn off in a standby mode. Accordingly, by turning on only when transmitting a signal in an active transmit mode, the BLE device 200 may decrease its power consumption, which may be advantageous for devices with a finite power source. As such, advertising protocols are designed to allow the BLE device 200 to advertise data to one or more computing devices while maintaining the low power consumption of BLE device 200.

Furthermore, BLE protocols include different types of advertising packets. The advertising packet type may at least specify a configuration of the BLE device 200. For instance, the advertising packet type may specify whether the BLE device 200 is connectable and/or scannable. A connectable BLE device may pair with another Bluetooth device, and a scannable BLE device may broadcast an advertising packet in response to receiving a scan request from another Bluetooth device. Furthermore, an advertising packet may be a directed packet. A directed packet may include the BLE's address and the receiver device's address, whereas an undirected packet may not be directed toward a particular receiver.

Accordingly, the configuration of the BLE device 200, which may be specified by the advertising packet type, may also affect the power consumption of the BLE device 200. For instance, a BLE device in a connectable and scannable configuration may use more power than a BLE device in a non-connectable and non-scannable configuration, as the BLE device in connectable and scannable configuration has a longer active transmit time than the BLE device operating in the non-connectable and non-scannable configuration.

As explained above, the BLE device 200 may operate only as a transmitter and, therefore, may not be able to operate in a connectable configuration. Furthermore, the transmitter may not be able to receive scan requests from other Bluetooth devices. Accordingly, in some embodiments, the BLE device 200 may be operating in a non-connectable and non-scannable configuration in order to decrease power consumption.

Note that there are other advantages to the BLE advertising protocols in addition to low power consumption of a BLE device operating in accordance with the advertising protocols. For example, in scenario 100, the computing devices 106 and 108 may discover Bluetooth devices located near the computing device faster (and consuming less energy) using advertising protocols than by using other protocols. Advertising protocols may use three fixed channels of a wireless spectrum, e.g., the 2.4 GHz wireless spectrum. Thus, by not scanning the full wireless spectrum, the computing devices 106 and 108 may detect other Bluetooth devices over the three fixed channels, allowing for receiving and sending BLE advertisement packets faster than other protocols.

Returning to FIG. 2, the BLE packetizer 202 may use the data included in the signal received via the HCl to generate a data signal, which may include one or more data packets. Accordingly, the BLE packetizer 202 may receive instructions to generate a data signal including one or more data packets according to the advertising protocol. Further, the instructions may detail the type of advertising event to broadcast. For instance, as explained above, the type of advertising event may determine whether the device is connectable and/or scannable, and/or whether the packet is directed. In an example, the BLE packetizer 202 may receive data indicative of instructions to generate a data signal that includes a non-connectable, non-scannable, and undirected advertising event.

FIG. 3 illustrates an example advertising packet. In particular, an advertising packet 300 may, for example, take the form of any advertising packets described above in relation to the FIG. 1. In some additional embodiments, a Bluetooth tag may communicate the advertisement packet 300. As shown in FIG. 3, advertising packet 300 may include preamble 302, access address 304, payload data unit (PDU) 306 with 2 to 39 bytes, and cyclic redundancy check (CRC) 308.

In addition, PDU 306 may include header 310 and advertisement payload 312 with 6 to 37 bytes. Further, advertisement payload 312 may include header 314, MAC address 316, and advertisement data 318 with up to 31 bytes. In an example, the 31 byte space may contain sensor data that may be communicated via the advertisement packet. The header 314 may include a type of the PDU 306. The type of PDU 306 may specify the type of the advertisement packet. As explained above, the advertisement packet type may be a non-connectable, non-scannable, and undirected packet type.

Returning to FIG. 2, the oscillator 204 may generate an RF carrier signal that may carry the data signal generated by the BLE packetizer 202. The RF signal carrying the data may then be broadcast by the BLE device 200. As illustrated in FIG. 2, the oscillator 204 may be a free-running oscillator, which may be used to directly generate an RF carrier signal. Thus, a free-running oscillator is an alternative to using a frequency synthesizer (e.g., Phase Locked Loop (PLL) synthesizer) to generate an RF carrier signal. Typically, a frequency synthesizer, which also includes a frequency reference circuit, may dissipate a significant portion of a transmitter's power. Accordingly, using a free-running oscillator may result in considerable power savings, which may be advantageous for low power devices.

Further, both the turn-on time for the frequency synthesizer to lock to its frequency reference and the turn-on time of its frequency reference circuit may be significant compared to the packet duration. Therefore, the turn-on time (i.e., the time to go from sleep mode to active transmit mode) for a transmitter using a frequency synthesizer may be greater than a transmitter using a free-running oscillator. A longer turn-on time may result in greater power dissipation. Accordingly, using the free-running oscillator, which may have a reduced turn-on time compared to a frequency synthesizer, may result in further power savings.

The free-running oscillator may directly generate the RF carrier signal, which may have a frequency within a wireless spectrum, e.g., the 2.4 GHz wireless spectrum. Within examples, the free-running oscillator may directly generate an RF carrier signal that has a frequency of one of the three channels in the 2.4 GHz band that are allocated to BLE advertising protocols according to Bluetooth specifications. The three channels are specified as 1 MHz wide channels with frequencies of 2.402 GHz, 2.480 GHz, and 2.426 GHz.

Note that the example oscillator provided in FIG. 2 and the accompanying description herein is for illustrative purposes only and should not be considered limiting. For instance, the BLE device 200 may include more than one free-running oscillator. In an example, the BLE device 200 may include three free-running oscillators, each of which may be used to generate a carrier signal at a frequency of the three BLE channels. In such examples, the BLE device 200 may utilize methods such as multichannel transmission and frequency hopping.

Within examples, the free-running oscillator 204 may include a Pierce oscillator circuit or a Colpitts oscillator circuit. The oscillator 204 may include a transistor, a biasing resistor, capacitors, and a resonator. The resonator, which may be located off of the IC of the BLE device 200, may be used as a filter to filter the oscillation frequency. Further, the total capacitance of the capacitors in the oscillator 204, as seen by the resonator, may be referred to as the “load capacitance.” The load capacitance may affect how far the oscillator loop is resonating, relative to the desired resonant frequency. Accordingly, selectively choosing the resonator, which may have a specific load capacitance requirement, may determine the oscillation frequency.

Within examples, the resonator in the oscillator 204 may be a thin-film bulk acoustic resonator (FBAR). An FBAR resonator may include a piezoelectric thin film between two metal layers. FBAR resonators are high-Q resonators that may have a stable and a low phase-noise center frequency, which may be the oscillation frequency. Within examples, FBAR resonators may have a Q of several hundred. In other examples, FBAR resonators may have an (unloaded) Q of over one thousand. Further, temperature compensation may be used to maintain the center frequency of the FBAR resonator at the frequency of the wireless channel.

Note that the example resonator discussed above is for illustrative purposes only and should not be considered limiting. For instance, the resonator may be any resonator that may be a high frequency resonator, which may provide an oscillation frequency with a stability and an accuracy that may meet Bluetooth standards. In other examples, the resonator may be a crystal resonator. In an example, the resonator may be a quartz resonator.

As noted above, the RF carrier signal generated by the oscillator 204 may be used to carry the data signal generated by the BLE packetizer 202. More specifically, the data signal generated by the BLE packetizer 202 may act as a tuning code, which may have a specific symbol rate. Further, the tuning code may be used to directly modulate the RF carrier signal. Accordingly, the modulated RF carrier signal may carry the data signal generated by the BLE packetizer 202. Within examples, the tuning code may modulate the RF carrier signal according to at least BLE protocols.

For instance, BLE protocols specify using Gaussian Frequency Shift Keying (GFSK) as the modulation scheme to modulate the RF carrier signal. Accordingly, the tuning code may be used to modulate the RF carrier signal to two different frequencies of the same advertising channel according to GFSK. Additionally and/or alternatively, the tuning code may be used to modulate the RF carrier signal to two different frequencies of the same advertising channel according to Binary Frequency Shift Keying (BFSK). The oscillator 204 may include a bank of switched capacitors, which may be used to adjust the load capacitance of the oscillator 204. As explained above, adjusting the load capacitance of the oscillator 204 may adjust the oscillation frequency. The digital data signal, indicative of digital “0” and “1,” may be used to modify the load capacitance of the oscillator 204, such that the oscillator 204 may generate a modulated signal of two frequencies, one of which corresponds to digital “0” and the other to digital “1.”

The modulated RF signal, carrying the data signal, may be transmitted to a class-D power amplifier 206 as illustrated in FIG. 2. However, also note that at least a portion of the modulated signal may be transmitted to a prescaler 208. The prescaler 208 may scale the signal and provide the scaled signal to the BLE packetizer 202, where it may be used as a clock source. For instance, the prescaler 208 may scale down the 2.48 GHz signal to a 1 MHz or 8 MHz signal. By using a portion of the carrier signal as a clock source for the BLE packetizer 202, there may be no need for a separate timing source for the BLE packetizer 202, thereby further increasing power savings.

Furthermore, as illustrated in FIG. 2, the modulated RF carrier signal may be amplified using the class-D power amplifier 206. The amplified signal may then be transmitted to the radio (represented as “RF” in FIG. 2) where it may be broadcast over the air. As explained above, in some embodiments, the BLE device 102 may be operating in advertising mode, which involves the BLE device 102 periodically transmitting advertising packets. Accordingly, the broadcast RF signal may include advertisement packets, which may be received by one or more Bluetooth devices.

The BLE device 200 may be powered by the powertrain 210. The powertrain may include a low dropout regulator (LDO) 228, a power on reset (PoR) 222, a bandgap voltage reference (Bandgap) 226, and a real time clock (RTC) 224. Note that the RTC 224 may have a low frequency and may operate without a crystal reference, as the BLE packetizer 202 may use a signal from the oscillator 204 as explained above.

FIGS. 4A and 4B illustrate example oscillator circuits for use in a BLE device. For example, the example oscillator circuits depicted in FIGS. 4A and 4B may serve as oscillator 204 in the BLE device 200 depicted in FIG. 2.

In particular, FIG. 4A illustrates a Pierce oscillator circuit 400. The Pierce oscillator circuit 400 may include a resonator 402, a transistor 404, capacitors C₁ 406 and C₂ 408, and a biasing resistor 410. As discussed above with respect to FIG. 2, the resonator 402 may be an FBAR resonator that oscillates at an RF frequency. In other examples, the resonator may be any resonator that may be a high frequency resonator, which may provide an oscillation frequency with a stability and an accuracy that may meet Bluetooth standards, such as a crystal resonator. While the transistor 404 is depicted in FIG. 4A as a metal-oxide-semiconductor field-effect transistor (MOSFET), the transistor 404 may be any type of amplifying transistor. In some examples, the transistor 404 may include more than one transistor and/or may take the form of an operational amplifier.

As depicted in FIG. 4A, a Pierce oscillator circuit includes a pi-network feedback circuit arrangement. In this arrangement, one terminal of the resonator 402 is connected to capacitor C₁ 406, and the other terminal of the resonator 402 is connected to capacitor C₂ 408, while capacitors C₁ 406 and C₂ 408 are coupled to ground. In operation, the FBAR resonator 402 may appear inductive at frequencies different from its resonant frequency, and the oscillation frequency of the FBAR resonator 402 may be adjusted by varying its load capacitance. Accordingly, by varying the capacitance of capacitors C₁ 406 and C₂ 408 the load capacitance of the FBAR resonator 402 may be varied, and, consequently, the oscillation frequency of the Pierce oscillator circuit 400 may be varied as well.

As noted above with respect to FIG. 2, the data signal generated by the BLE packetizer 202 may act as a tuning code that may be used to directly modulate an RF signal generated by the Pierce oscillator circuit 400, such that the modulated RF signal may carry the data signal generated by the BLE packetizer 202. Within examples, the tuning code may modulate the RF signal generated by the Pierce oscillator circuit 400 according to at least BLE protocols.

For instance, the tuning code may be used to modulate the RF signal to two different frequencies of the same advertising channel according to GFSK. Additionally and/or alternatively, the tuning code may be used to modulate the RF signal to two different frequencies of the same advertising channel according to BFSK. In some examples, the capacitors C₁ 406 and C₂ 408 may include a bank of switched capacitors, which may be used to adjust the load capacitance of the FBAR resonator 402. As explained above, adjusting the load capacitance of the FBAR resonator 402 may adjust the oscillation frequency of the Pierce oscillator circuit 400. The digital data signal, indicative of digital “0” and “1,” may be used to modify the load capacitance of the FBAR resonator 402, such that the Pierce oscillator circuit 400 may generate a modulated signal of two frequencies, one of which corresponds to digital “0” and the other to digital “1.”

FIG. 4B illustrates a Colpitts oscillator circuit 420. Similar to the Pierce oscillator circuit 400, the Colpitts oscillator circuit 420 may include a resonator 422, a transistor 424, capacitors C₁ 426 and C₂ 428, and a biasing resistor 430. As discussed above with respect to FIG. 2, the resonator 422 may be an FBAR resonator that oscillates at an RF frequency. In other examples, the resonator may be any resonator that may be a high frequency resonator, which may provide an oscillation frequency with a stability and an accuracy that may meet Bluetooth standards, such as a crystal resonator. While the transistor 424 is depicted in FIG. 4B as a MOSFET, the transistor 424 may be any type of amplifying transistor. In some examples, the transistor 424 may include more than one transistor and/or may take the form of an operational amplifier.

As depicted in FIG. 4B, a Colpitts oscillator circuit 420 includes a capacitive voltage divider feedback circuit arrangement. In this arrangement, capacitors C₁ 426 and C₂ 428 are coupled in series to form a voltage divider. One terminal of the resonator 422 is connected to the transistor 424, and the other terminal of the resonator 422 is connected to ground. In operation, the FBAR resonator 422 may appear inductive at frequencies different from its resonant frequency, and the oscillation frequency of the FBAR resonator 422 may be adjusted by varying its load capacitance. Accordingly, by varying the capacitance of capacitors C₁ 426 and C₂ 428 the load capacitance of the FBAR resonator 422 may be varied, and, consequently, the oscillation frequency of the Colpitts oscillator circuit 420 may be varied as well.

As noted above with respect to FIG. 2, the data signal generated by the BLE packetizer 202 may act as a tuning code that may be used to directly modulate an RF signal generated by the Colpitts oscillator circuit 420, such that the modulated RF signal may carry the data signal generated by the BLE packetizer 202. Within examples, the tuning code may modulate the RF signal generated by the Colpitts oscillator circuit 420 according to at least BLE protocols.

For instance, the tuning code may be used to modulate the RF signal to two different frequencies of the same advertising channel according to GFSK. Additionally and/or alternatively, the tuning code may be used to modulate the RF signal to two different frequencies of the same advertising channel according to BFSK. In some examples, the capacitors C₁ 426 and C₂ 428 may include a bank of switched capacitors, which may be used to adjust the load capacitance of the FBAR resonator 422. As explained above, adjusting the load capacitance of the FBAR resonator 422 may adjust the oscillation frequency of the Colpitts oscillator circuit 420. The digital data signal, indicative of digital “0” and “1,” may be used to modify the load capacitance of the FBAR resonator 422, such that the Colpitts oscillator circuit 420 may generate a modulated signal of two frequencies, one of which corresponds to digital “0” and the other to digital “1.”

Note that the example oscillator circuits provided in FIGS. 4A and 4B and the accompanying description herein is for illustrative purposes only and should not be considered limiting. For instance, the oscillator circuits may include additional and/or alternative components than depicted.

In some examples, an oscillator, such as oscillator 204 of BLE device 200 depicted in FIG. 2, may include three Pierce oscillator circuits 400, each of which may be used to generate a carrier signal at a frequency of one of the three BLE channels. In some examples, an oscillator, such as oscillator 204 of BLE device 200 depicted in FIG. 2, may include three Colpitts oscillator circuits 420, each of which may be used to generate a carrier signal at a frequency of one of the three BLE channels.

In examples where the BLE device 200 includes more than one of the Pierce oscillator circuits 400 or Colpitts oscillator circuits 420, the BLE device 200 may modulate each of the RF carrier signals generated by the Pierce oscillator circuits 400 or Colpitts oscillator circuits 420 to carry the data signal generated by the BLE packetizer 202. In this manner, the data signal generated by the BLE packetizer 202 may be concurrently broadcast on each of the RF carrier signals. In one example, the data signal generated by the BLE packetizer 202 may be concurrently broadcast on all three BLE channels.

In other examples where the BLE device 200 includes more than one of the Pierce oscillator circuits 400 or Colpitts oscillator circuits 420, the BLE device 200 may modulate one or two of the RF carrier signals generated by the Pierce oscillator circuits 400 or Colpitts oscillator circuits 420 to carry the data signal generated by the BLE packetizer 202. In this manner, the data signal generated by the BLE packetizer 202 may be broadcast on only one of the three BLE channels or concurrently broadcast on two of the three BLE channels.

Still in other examples where the BLE device 200 includes more than one of the Pierce oscillator circuits 400 or Colpitts oscillator circuits 420, the BLE device 200 may employ time division multiplexing (TDM) to modulate the RF carrier signals generated by the Pierce oscillator circuits 400 or Colpitts oscillator circuits 420 to carry the data signal generated by the BLE packetizer 202. In this manner, the data signal generated by the BLE packetizer 202 may be carried on a first RF signal (e.g., a 2.402 GHz signal) for a given amount of time, then carried on a second RF signal (e.g., a 2.480 GHz signal) for a given amount of time, and then carried on a third RF signal (e.g., a 2.426 GHz signal) for a given amount of time. Note that, in some examples, TDM may be used to carry the data signal on more or fewer than three RF signals.

As noted, reducing the size and power consumption of a BLE device allows for longer operation and more versatile applications and/or uses. Accordingly, it may be advantageous to generate multiple carrier signals with a single oscillator circuit. FIGS. 5A and 5B depict example oscillator circuits that produce multiple carrier signals for use in a BLE device. In some examples, the oscillator circuits depicted in FIGS. 5A and 5B may serve as oscillator 204 in the BLE device 200 depicted in FIG. 2.

FIG. 5A illustrates a Pierce oscillator circuit 500. Like the Pierce oscillator circuit 400 depicted in FIG. 4A, Pierce oscillator circuit 500 may include a transistor 504, capacitors C₁ 506 and C₂ 508, and a biasing resistor 510. However, rather than including a single resonator, the Pierce oscillator circuit 500 may include a number of resonators 502. The resonators 502 may be FBAR resonators or high frequency resonator that may provide an oscillation frequency with a stability and an accuracy that may meet Bluetooth standards, such as crystal resonators.

As depicted in FIG. 5A, the Pierce oscillator circuit 500 includes three resonators 502. Each of the three resonators 502 may respectively oscillate at one of the frequencies of the three BLE channels. Note that, in other examples, the Pierce oscillator circuit 500 may include more or fewer than three resonators, and the resonators may oscillate at various frequencies.

In operation, a switch 512 may toggle between terminals of the resonators 502, such that only one of the resonators 502 is connected to the Pierce oscillator circuit 500 at any given time. As illustrated in FIG. 5A, the switch 512 may connect a terminal on one side of the resonators 502 to capacitor C₁ 506 while the terminals on the other side of the resonators remain coupled to capacitor C₂ 508. In another example, the switch 512 may connect a terminal on one side of the resonators 502 to capacitor C₂ 508 while the terminals on the other side of the resonators remain coupled to capacitor C₁ 506. In another example, the switch 512 may connect a terminal on one side of the resonators 502 to capacitor C_(i) 506 and a terminal on the other side of the resonators 502 to capacitor C₂ 508. The switch 512 may have a low resistance to minimize power loss and performance degradation of the Pierce oscillator circuit 500. Further, the switch 512 may have a low capacitance to minimize capacitive loading of the resonators 502.

In some examples, a BLE device, such as the BLE device 200 illustrated in FIG. 2, may employ time division multiplexing when toggling the switch 512. In this manner, the Pierce oscillator circuit 500 may generate a first RF signal with one of the resonators 502 for a given period of time, a second RF signal with another one of the resonators 502 for a given period of time, and a third RF signal with yet another one of the resonators 502 for a given period of time. In some examples, each of these three RF signals may have a respective frequency within the three respective BLE channels. Further, each of these RF signals may be modulated by the data signal generated by the BLE packetizer 202, amplified by the amplifier 206, and broadcast over the air. In other examples, time division multiplexing may be used similarly to select between more or fewer than three RF signals.

FIG. 5B illustrates a Colpitts oscillator circuit 520. Like the Colpitts oscillator circuit 420 depicted in FIG. 4B, Colpitts oscillator circuit 520 may include a transistor 524, capacitors C₁ 526 and C₂ 528, and a biasing resistor 530. However, rather than including a single resonator, the Colpitts oscillator circuit 520 may include a number of resonators 522. The resonators 522 may be FBAR resonators or high frequency resonator that may provide an oscillation frequency with a stability and an accuracy that may meet Bluetooth standards, such as crystal resonators.

As depicted in FIG. 5B, the Colpitts oscillator circuit 520 includes three resonators 522. Each of the three resonators 522 may respectively oscillate at one of the frequencies of the three BLE channels. In some examples, the Colpitts oscillator circuit 520 may include more or fewer than three resonators, and the resonators may oscillate at various frequencies.

In operation, a switch 532 may toggle between terminals of the resonators 522, such that only one of the resonators 522 is connected to the Colpitts oscillator circuit 520 at any given time. As illustrated in FIG. 5B, the switch 532 may connect a terminal on one side of the resonators 522 to the transistor 524 while the terminals on the other side of the resonators remain coupled to ground. In another example, the switch 532 may connect a terminal on one side of the resonators 522 to ground while the terminals on the other side of the resonators remain coupled to the transistor 524. In another example, the switch 532 may connect a terminal on one side of the resonators 522 to the transistor 524 and a terminal on the other side of the resonators 522 to ground. The switch 532 may have a low resistance to minimize power loss and performance degradation of the Colpitts oscillator circuit 520. Further, the switch 532 may have a low capacitance to minimize capacitive loading of the resonators 522.

In some examples, a BLE device, such as the BLE device 200 illustrated in FIG. 2, may employ time division multiplexing when toggling the switch 532. In this manner, the Colpitts oscillator circuit 520 may generate a first RF signal with one of the resonators 522 for a given period of time, a second RF signal with another one of the resonators 522 for a given period of time, and a third RF signal with yet another one of the resonators 522 for a given period of time. In some examples, each of these three RF signals may have a respective frequency within the three respective BLE channels. Further, each of these RF signals may be modulated by the data signal generated by the BLE packetizer 202, amplified by the amplifier 206, and broadcast over the air. In other examples, time division multiplexing may be used similarly to select between more or fewer than three RF signals.

As noted previously, the resonator or resonators of the oscillator 204 may be located on a separate IC from the oscillator 204. In order to further reduce the size of a BLE device, multiple resonators may be fabricated on a single die.

FBAR resonators may take one of two general forms: longitudinal and shear mode. To fabricate a longitudinal FBAR resonator, a thin metal film, such as platinum (Pt) and/or titanium (Ti), among other metals, may be deposited on a substrate, such as silicon (Si). The thin metal film may serve as an electrode for the FBAR resonator. A piezoelectric material, such as aluminum nitride (AlN) or zinc oxide (ZnO), may then be deposited on the thin metal film. The resonant frequency of the FBAR resonator may be controlled by varying the thickness of the piezoelectric material, since the resonant frequency is inversely proportional to the thickness of the piezoelectric material. After depositing the piezoelectric material, another thin metal film may be deposited on the piezoelectric material, forming the other electrode of the FBAR resonator. During fabrication, both the thin metal film and the piezoelectric material may be deposited using physical vapor deposition (PVD) or chemical vapor deposition (CVD).

To fabricate a shear mode FBAR resonator, the piezoelectric material may be deposited on the substrate, and two strips of thin metal film may be deposited on the piezoelectric material. The metal strips form the two electrodes of the FBAR resonator, and the resonant frequency of the FBAR resonator is inversely proportional to the distance between the two electrodes.

In order to fabricate multiple FBAR resonators on a single die, either or both of the above-described processes may be carried out for each FBAR resonator. However, rather than fabricating the FBAR resonators simultaneously, portions of the die may be masked off with a photoresist, allowing fabrication of individual FBAR resonators.

FIGS. 6A illustrates a chip 600 with multiple resonators fabricated on a single die 604. The chip 600 includes three resonators 602 a-c and six pads 606, two coupled to each of the resonators 602 a-c. The resonators 602 a-c are FBAR resonators, where each of the resonators 602 a-c has a resonant frequency different from the other resonators.

To fabricate chip 600, resonator 602 a may be fabricated according to a process described above. Resonator 602 a may then be masked with a photoresist, and resonator 602 b may be fabricated. Finally, resonators 602 a and 602 b may be masked with a photoresist, and resonator 602 c may be fabricated. By fabricating the resonators individually, resonators 602 a-c may be fabricated with varying thicknesses and, therefore, distinct resonant frequencies from one another. In some examples, one of the resonators 602 a-c may be fabricated with a resonant frequency within the 2.402 GHz BLE channel, another of the resonators 602 a-c may be fabricated with a resonant frequency within the 2.480 GHz BLE channel, and another of the resonators 602 a-c may be fabricated with a resonant frequency within the 2.426 GHz BLE channel.

The chip 600 may be used with any of the oscillator circuits depicted in FIGS. 4A, 4B, 5A, and 5B. However, chip 600 includes connections to two pads 606 for each of the resonators 602 a-c. More interconnects between circuits may increase the overall size of the BLE device. Accordingly, the number of interconnects may be lowered to reduce the size of the BLE device.

FIG. 6B illustrates another chip 620 with three resonators 622 a-c fabricated on a single die 624 according to similar methods for fabricating the chip 600 illustrated in FIG. 6A. However, unlike chip 600, chip 620 only includes four pads 626 a-d. Three of the pads 626 a-c are coupled to one electrode of each of the three resonators 622 a-c, respectively, while the fourth pad 626 d is coupled to the other electrode of all three resonators 622 a-c.

Thus, chip 620 allows for further size reduction of a BLE device when compared to chip 600 by reducing the number of pads and interconnects. Chip 620 may be particularly suitable for use with the Colpitts oscillator circuits depicted in FIGS. 4B and 5B, because the resonators 422 and 522 may share a ground connection. Similarly, chip 620 may be used with the Pierce oscillator circuit depicted in FIG. 5A, because the resonators 502 share a connection to capacitor C₂ 508. However, chip 620 may be less suitable for use with three of the oscillator circuits depicted in FIG. 4A, because each of the resonators 402 has two distinct connections to capacitors C₁ 406 and C₂ 408. Accordingly, the resonators 402 in three separate Pierce oscillator circuits 400 do not share a connection that can use the fourth pad 626 d of chip 620.

While FIGS. 6A and 6B depict chips with three FBAR resonators, it should be noted that more or fewer than three FBAR resonators may be fabricated on a single die, and the number of pads connected to the FBAR resonator electrodes may be adjusted accordingly.

FIG. 7 illustrates a flow diagram of an example method for broadcasting an advertisement event on a wireless channel. Accordingly, a BLE device, such as the BLE device 200, may transmit a signal to one or more computing devices by carrying out one or more steps, processes, and/or functions as illustrated by one or more of blocks 702 through 710 of FIG. 7.

In particular, method 700 of FIG. 7 may be carried out or implemented by one or more of the Bluetooth devices described above. For example, method 700 may be carried out by the device 102 in FIG. 1 to broadcast an advertisement packet to computing devices 106 and 108.

Further, method 700 may include one or more steps, processes, and/or functions as illustrated by one or more of blocks 702 through 710. Although the blocks are illustrated in a sequential order, a number of these blocks may also be performed simultaneously and/or in a different order than those illustrated. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based upon specific implementations.

At block 702, the method 700 includes generating, based on data, a data signal comprising one or more data packets. The data may include information such as encryption parameters, modulation parameters, mode of operation of the device, packet type, etc. The data may further include certain data that may be included in the data packet. Further, the data packet may be a non-connectable, non-scannable advertising packet.

At block 704, the method 700 further includes generating a plurality of RF signals of different frequencies using an oscillator circuit. Within examples, the oscillator circuit may be one or more of the oscillator circuits described in relation to FIGS. 4A, 4B, 5A, and 5B. Accordingly, one or more Pierce oscillator circuits with one or more FBAR resonators, or one or more Colpitts oscillator circuits with one or more FBAR resonators, may directly generate the RF signals.

In some examples, the plurality of RF signals may be generated by three Pierce oscillator circuits, such as the Pierce oscillator circuits 400 depicted in FIG. 4A. The three Pierce oscillator circuits may concurrently generate three RF signals having three different frequencies (e.g., frequencies within the 2.402 GHz, 2.480 GHz, and 2.426 GHz BLE channels). Alternatively, time division multiplexing may be used to alternate between frequencies. Further, to reduce overall circuit size, the Pierce oscillator circuits may include FBAR resonators fabricated on a single chip, such as chip 600.

In other examples, the plurality of RF signals may be generated by three Colpitts oscillator circuits, such as the Colpitts oscillator circuits 420 depicted in FIG. 4B. The three Colpitts oscillator circuits may concurrently generate three RF signals having three different frequencies (e.g., frequencies within the 2.402 GHz, 2.480 GHz, and 2.426 GHz BLE channels). Alternatively, time division multiplexing may be used to alternate between frequencies. Further, to reduce overall circuit size, the Colpitts oscillator circuits may include FBAR resonators fabricated on a single chip, such as chip 600 or chip 620.

In other examples, the plurality of RF signals may be generated by a single Pierce oscillator circuit with three FBAR resonators, such as the Pierce oscillator circuit 500 depicted in FIG. 5A. The three FBAR resonators may be fabricated on a single chip, such as chip 600 or chip 620 and may have three different resonant frequencies (e.g., frequencies within the 2.402 GHz, 2.480 GHz, and 2.426 GHz BLE channels). Time division multiplexing may be used to switch one of the three FBAR resonators into the circuit at a time in order to alternate between frequencies generated by the oscillator circuit.

Still in other examples, the plurality of RF signals may be generated by a single Colpitts oscillator circuit with three FBAR resonators, such as the Colpitts oscillator circuit 520 depicted in FIG. 5B. The three FBAR resonators may be fabricated on a single chip, such as chip 600 or chip 620 and may have three different resonant frequencies (e.g., frequencies within the 2.402 GHz, 2.480 GHz, and 2.426 GHz BLE channels). Time division multiplexing may be used to switch one of the three FBAR resonators into the circuit at a time in order to alternate between frequencies generated by the oscillator circuit.

As shown by block 706, the method 700 further includes directly modulating at least one of the RF signals, based on the data signal, to generate a modulated RF signal. As noted above, the modulated RF signal may conform to BLE protocols. Further, at least one of the RF signals may be directly modulated, for example, by using the data signal to adjust the load capacitance of an oscillator circuit using a bank of switched capacitors.

At block 708, the method 700 further includes amplifying the modulated RF signal. As noted above, the signal may be amplified using a class-D amplifier. Finally, the method 700 further includes broadcasting the amplified RF signal on the wireless channel. For instance, the wireless channel may be a channel in the 2.4 GHz spectrum.

It should be noted that FIG. 2 may correspond to hardware, chipsets, and/or circuitry that are designed or wired to perform the specific logical functions in method 700. Further, each block in method 700 may represent a module, a segment, or a portion of program code, which includes one or more instructions executable by a processor for implementing specific logical functions or steps in the process. The program code may be stored on any type of computer readable medium, for example, such as a storage device including a disk or hard drive.

FIG. 8 illustrates a block diagram of an example Bluetooth device 800. In particular, Bluetooth device 800 may, for example, take the form of any of the computing devices and Bluetooth devices described above in relation to FIGS. 1 and 2. In particular, Bluetooth device 800 may, for example, be combined with any of the computing devices described in the scenarios above. In some instances, Bluetooth device 800 may include the BLE device 200. For example, Bluetooth device 800 may be a sensor, a phone (i.e., a computing device), a digital television, a monitor, a tablet computer, wearable computing devices, and/or a human-interface device. Other examples are possible as well.

As illustrated in FIG. 8, the Bluetooth device 800 may include an application manager 802, a host stack 806, a controller 810, and a radio 818. In particular, the application manager 802 may be coupled to the host stack 806 by a system bus 804 or a similar mechanism. Further, the host stack 806 may be coupled to the controller 810 by a system bus 808 or a similar mechanism. In some embodiments, the interface between the host stack 806 and the controller 810 may be referred to as HCl. Yet further, the controller 810 may be coupled to the radio 818 by a system bus 812 or similar mechanism.

In some examples, the application manager 802, host stack 806, and the controller 810 may be implemented on a single IC chip, which may referred to as a “system-on-chip (SOC).” Accordingly, in a SOC implementation, the three layers may be implemented simultaneously on a low power processor. In other examples, the controller 810 may be implemented on a separate processor from the host stack 806. For instance, the controller 810 may be implemented on a low power processor on a device (i.e., the BLE device 200), while the host stack 806 is implemented on a processor of a host computing device.

As illustrated, the controller 810 may include a link layer 814 (LL) and a physical controller interface 816 (PHY). The link layer 814, which may manage the configuration of the Bluetooth device, may directly interact with the physical controller interface 816, which may include the hardware for generating a signal. The link layer 814, on the other hand, may be implemented using a combination of hardware and software. Accordingly, the physical controller interface 816 and link layer 814 may be implemented in Bluetooth device 800 using the BLE device 200.

Accordingly, in examples where the physical controller interface 816 may be implemented using the BLE device 200, the Bluetooth device 800 may operate in an advertising mode. More specifically, the Bluetooth device 800 may broadcast advertising packets on one of the BLE advertising channels. The specific channel onto which the Bluetooth device 800 may be advertised may depend on the BLE device 200. Further, the broadcast advertising packets may be non-connectable, non-scannable, and undirected advertising packets.

In some embodiments, the Bluetooth device 800 may be in advertising mode to broadcast an advertising packet 820 to one or more computing devices. FIG. 9 is a block diagram of an example computing device 900. In some instances, computing device 900 may, for example, take the form of any computing device described above in relation to FIG. 1 or a similar device that may be configured to perform the methods and functions described herein. In this example, computing device 900 includes a processor 902, data storage 904, a network interface 906, and an input/output function 908, all of which may be coupled by a system bus 910 or a similar mechanism. Processor 902 can include one or more CPUs, such as one or more general purpose processors and/or one or more dedicated processors (e.g., application specific integrated circuits, digital signal processors, network processors, application processing unit, etc.).

Data storage 904, in turn, may comprise volatile and/or non-volatile data storage and can be integrated in whole or in part with processor 902. Data storage 904 can hold program instructions, executable by processor 902, and data that may be manipulated by these instructions to carry out the various methods, processes, or functions described herein. Alternatively, these methods, processes, or functions can be defined by hardware, firmware, and/or any combination of hardware, firmware, and software. By way of example, the data in data storage 904 may contain program instructions, perhaps stored on a non-transitory, computer-readable medium, executable by processor 902 to carry out any of the methods, processes, or functions disclosed in this specification or the accompanying drawings.

Network interface 906 may take the form of a wireless connection, such as Bluetooth. In particular, network interface 906 may enable one or more Bluetooth standards or protocols, including BLE protocols and related advertising protocols. For example, referring back to FIG. 1, computing device 106 may also include network interface 906 to pair with computing device 108. In addition, network interface 906 may take the form of other wireless connections, such as IEEE 802.11 (Wi-Fi), or a wide-area wireless connection. However, other forms of physical layer connections and other types of standard or proprietary communication protocols may be used over network interface 906. Furthermore, network interface 906 may comprise multiple physical interfaces. Further, network interface 906 may take the form of a wireline connection, such as an Ethernet connection.

Input/output function 908 may facilitate user interaction with example computing device 900. Input/output function 908 may comprise multiple types of input devices, such as a keyboard, a mouse, a touch screen, and so on. Similarly, input/output function 908 may comprise multiple types of output devices, such as a screen, monitor, printer, or one or more light emitting diodes (LEDs). Additionally or alternatively, example computing device 900 may support remote access from another device, via network interface 906 or via another interface (not shown), such as a universal serial bus (USB) or high-definition multimedia interface (HDMI) port.

In some embodiments, the computing device 900 may include a device platform or operating system (not shown). In some instances, the device platform or the operating system may be compatible with Bluetooth, Bluetooth Low Energy (BLE) protocols, and/or BLE advertising protocols. In some instances, the device platform or the operating system may be configured as a multi-layered Linux platform or operating system. The device platform may include different applications and an application framework, as well as various kernels, libraries, and runtime entities. In other examples, other formats or systems may operate the computing device 900 as well.

Accordingly, Bluetooth device 800 may transmit advertising packet 820 which may be received by computing device 900. In particular, an application may be downloaded on Bluetooth device 800 or on a computing device combined with Bluetooth device 800. Further, the application may exchange advertisement data with application manager 802 through an application interface. Yet further, the applications may communicate with application manager 802 to transmit the advertisement packet 820 to other devices (not shown in FIG. 8), such as computing device 900.

In some embodiments, Bluetooth device 800 may enter advertisement mode to transmit an advertising packet over the air for one or more applications. In some examples, the application of the Bluetooth device 800 may be predetermined. For instance, the Bluetooth device 800 may be a location beacon. In an example, the Bluetooth beacon 800 may be located inside of a building (e.g., an office building, store, etc.). Further, a computing device 900 may be located in proximity to the Bluetooth beacon 800. When the Bluetooth beacon 800 transmits advertising packets, it may transmit the advertising packet with location data. Depending on the specific embodiment, the location data can take many different forms. For example, the Bluetooth beacon 800 may be configured to provide data related to a location of the respective Bluetooth beacon either via relative position information or geographic coordinate system data. In another example, the Bluetooth beacon 800 may provide the computing device 900 with global location data.

These reference advertisement packets may correspond to a location that is known by the computing device 900, such as the entrance to a building. In other embodiments, the computing device 900 may receive data wirelessly including a set of reference advertisement packets. For example, when entering a building, the Bluetooth beacon 800 may communicate a set of data that relates to reference advertisement packets that the computing device 900 can expect to receive when stepping foot inside the store.

In another example, the Bluetooth device 800 may include a sensor 822. As illustrated, the sensor 822 may exchange data with the application manager 802 through the application interface 824. For instance, the Bluetooth device 800 may broadcast advertising packets, which may include data collected by the sensor 822, which the application manager 802 may receive through the application interface 824. For instance, the Bluetooth device 800 may be a body-mountable device configured to be mounted to a skin surface (e.g., to skin of the upper arm or abdomen of a person), with one or more sensors for quantitatively and qualitatively testing an analyte concentration in interstitial fluid (e.g., glucose in interstitial fluid) in situ and in real-time. Those of skill in the art will recognize that the sensing platform described herein may be provided in devices that could be mounted on a variety of portions of the human body to measure concentrations of an analyte in other fluids than interstitial fluid (e.g., to measure an analyte in a tear fluid, blood, saliva, or some other fluid or tissue of the body). Accordingly, the Bluetooth device 800 may be used for monitoring or detecting a user's health state. Further, the Bluetooth device 800 may broadcast, using the BLE device 200, sensor readings to a user's computing device 900.

The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims.

The above detailed description describes various features and functions of the disclosed systems, devices, and methods with reference to the accompanying figures. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The example embodiments described herein and in the figures are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

A block that represents a processing of information may correspond to circuitry that can be configured to perform the specific logical functions of a herein-described method or technique. Alternatively or additionally, a block that represents a processing of information may correspond to a module, a segment, or a portion of program code (including related data). The program code may include one or more instructions executable by a processor for implementing specific logical functions or actions in the method or technique. The program code and/or related data may be stored on any type of computer readable medium such as a storage device including a disk or hard drive or other storage medium.

The computer readable medium may also include non-transitory computer readable media such as computer-readable media that stores data for short periods of time like register memory, processor cache, and random access memory (RAM). The computer readable media may also include non-transitory computer readable media that stores program code and/or data for longer periods of time, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. A computer readable medium may be considered a computer readable storage medium, for example, or a tangible storage device.

Moreover, a block that represents one or more information transmissions may correspond to information transmissions between software and/or hardware modules in the same physical device. However, other information transmissions may be between software modules and/or hardware modules in different physical devices.

The particular arrangements shown in the figures should not be viewed as limiting. It should be understood that other embodiments can include more or less of each element shown in a given figure. Further, some of the illustrated elements can be combined or omitted. Yet further, an example embodiment can include elements that are not illustrated in the figures.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims. 

1. A method of broadcasting an advertisement event on a wireless channel, the method comprising: generating, based on data, a data signal comprising one or more data packets, wherein each of the one or more data packets is a non-connectable data packet; generating a radio frequency (RF) signal using a single oscillator circuit that can be selectively coupled to a plurality of thin-film bulk acoustic resonators (FBARs); directly modulating the generated RF signal, based on the data signal, to generate a modulated RF signal; amplifying the modulated RF signal; and broadcasting the amplified modulated RF signal on the wireless channel, wherein the amplified modulated RF signal is associated with the advertisement event.
 2. The method of claim 1, wherein the plurality of FBARs comprises a first FBAR having a first resonant frequency, a second FBAR having a second resonant frequency, and a third FBAR having a third resonant frequency.
 3. (canceled)
 4. (canceled)
 5. The method of claim 1, wherein the single oscillator circuit comprises a single Colpitts oscillator circuit that can be selectively coupled to each FBAR of the plurality of FBARs.
 6. The method of claim 1, wherein the single oscillator circuit comprises a single Pierce oscillator circuit that can be selectively coupled to each FBAR of the plurality of FBARs.
 7. The method of claim 1, wherein the data signal is generated using a Bluetooth Low Energy (BLE) packetizer, wherein the BLE packetizer uses a clock signal to generate the data signal, and wherein the clock signal is based on an output of the oscillator circuit.
 8. The method of claim 1, wherein the one or more data packets are based on a Bluetooth Low Energy (BLE) protocol.
 9. The method of claim 1, wherein generating the RF signal comprises selectively coupling the single oscillator circuit to a first FBAR of the plurality of FBARs.
 10. The method of claim 1, wherein the plurality of FBARs are located on a single die.
 11. The method of claim 10, wherein the single die comprises a first FBAR having a first resonant frequency, a second FBAR having a second resonant frequency, and a third FBAR having a third resonant frequency.
 12. A broadcasting device comprising: a packetizer that can generate, based on data, a data signal comprising one or more data packets, wherein each of the one or more data packets is a non-connectable data packet; a single oscillator circuit that can generate a plurality of radio frequency (RF) signals of different frequencies by selectively coupling the single oscillator circuit to a plurality of thin-film bulk acoustic resonators (FBARs), wherein at least one of the plurality of RF signals is directly modulated based on the data signal to generate a modulated RF signal; a power amplifier that can amplify the modulated RF signal; and an antenna that can broadcast the amplified modulated RF signal in a wireless channel as an advertisement event.
 13. The broadcasting device of claim 12, wherein the oscillator plurality of FBARs comprises a first FBAR having a first resonant frequency, a second FBAR having a second resonant frequency, and a third FBAR having a third resonant frequency.
 14. (canceled)
 15. (canceled)
 16. The broadcasting device of claim 12, wherein the single oscillator circuit comprises a single Colpitts oscillator circuit that can be selectively coupled to each FBAR of the plurality of FBARs.
 17. The broadcasting device of claim 12, wherein the single oscillator circuit comprises a single Pierce oscillator circuit that can be selectively coupled to each FBAR of the plurality of FBARs.
 18. A system comprising: one or more processors; a packetizer that can receive data from the one or more processors and generate, based on the received data, a data signal comprising one or more data packets, wherein each of the one or more data packets is a non-connectable data packet; a plurality of thin-film bulk acoustic resonators (FBARs) arranged on a single die; a single oscillator circuit that can generate a plurality of radio frequency (RF) signals of different frequencies by selectively coupling the single oscillator circuit to the plurality of FBARs, wherein at least one of the plurality of RF signals is directly modulated based on the generated data signal to generate a modulated RF signal; a power amplifier that can amplify the modulated RF signal; and an antenna that can broadcast the amplified modulated RF signal in a wireless channel as an advertisement event.
 19. (canceled)
 20. (canceled)
 21. The method of claim 2, wherein the first resonant frequency is 2.402 GHz, the second resonant frequency is 2.426 GHz, and the third resonant frequency is 2.48 GHz.
 22. The method of claim 9, wherein generating the RF signal further comprises: after selectively coupling the single oscillator circuit to the first FBAR of the plurality of FBARs, decoupling the single oscillator circuit from the first FBAR; and coupling the single oscillator circuit to a second FBAR of the plurality of FBARs.
 23. The broadcasting device of claim 13, wherein the single oscillator circuit can generate a first RF signal of the plurality of RF signals by selectively coupling the single oscillator circuit to a first FBAR of the plurality of FBARs.
 24. The broadcasting device of claim 23, wherein generating the single oscillator circuit can generate a second RF signal of the plurality of RF signals by: after selectively coupling the single oscillator circuit to the first FBAR of the plurality of FBARs, decoupling the single oscillator circuit from the first FBAR; and coupling the single oscillator circuit to a second FBAR of the plurality of FBARs.
 25. The system of claim 18, wherein the single oscillator circuit can generate a first RF signal of the plurality of RF signals by selectively coupling the single oscillator circuit to a first FBAR of the plurality of FBARs.
 26. The system of claim 18, wherein generating the single oscillator circuit can generate a second RF signal of the plurality of RF signals by: after selectively coupling the single oscillator circuit to the first FBAR of the plurality of FBARs, decoupling the single oscillator circuit from the first FBAR; and coupling the single oscillator circuit to a second FBAR of the plurality of FBARs. 